(625z) Conversion of Glycerol to Microbial Lipids By Cryptococcus Curvatus for Biodiesel Production

Authors: 
AmirSadeghi, M., Mississippi State University
Zhang, G., Mississippi State University
French, W. T., Mississippi State University
Hernandez, R., University of Louisiana at Lafayette
Holmes, W., University of Louisiana at Lafayette

The production of biofuels from biomass is considered a pivotal approach to face soaring energy prices, potential depletion of crude oils reservoirs, reduce greenhouse gas emissions, and enhance energy sustainability. Glycerol has been demonstrated to serve as a sole carbon and energy source for the production of microbial lipids. Integrating the low-value crude glycerol streams as substrates for microbial lipid production could enhance the productivity of the biodiesel facilities. In this work, Cryptococcus curvatus was tested for the production of lipids from glycerol as feedstock for biodiesel production.  C. curvatus was initially grown with N-acetyl-glucosamine as sole carbon and energy source at 30 ℃ for 60 hours. Then, cells of C. curvatus were harvested and transferred to a fresh nitrogen-free medium with glycerol as sole carbon and energy source for lipid production. Temperature, yeast extract, and initial concentration of glycerol were evaluated for optimization of lipid production.  Results showed that the addition of yeast extract enhanced lipid production. A temperature of 35℃ was optimal for lipid production. The composition of the produced lipids was determined to be favorable as a biodiesel feedstock when compared to those of traditional plant oil feedstock. Kinetic models using the logistic equation, and Luedeking-Piret equation were applied to describe non-lipid biomass, lipid production, and substrate utilization.